CN203586770U - Sintering machine with pre-cooling zone - Google Patents

Abstract

The utility model relates to a sintering machine, especially a sintering machine for iron ore pellets (GP, FP), which has a drying zone (TRZ) and a heating zone (WZ) adjacent to the drying zone immediately downstream. , the combustion zone (BRZ) adjacent to the heating zone, the waste heat utilization zone (REZ) and the cooling zone (KZ) adjacent to the combustion zone, the sintering machine also has: from the drying zone (TRZ) and heating zone (WZ) The first output duct for discharging warm air; and the second output duct for discharging hot air from the combustion zone (BRZ) and the waste heat utilization zone (REZ); Pre-cooling zone (VKZ); input duct for supplying mixed air consisting of fresh air, warm air and hot air to the pre-cooling zone (VKZ) with an inlet for fresh air; and from the first output duct and the second output The pipe leads to the connection pipe of the input pipe.

Description

Sintering machine with pre-cooling zone

technical field

The utility model relates to a sintering machine, in particular to a sintering machine for iron ore pellets. the

Background technique

Raw materials are often pelletized. For example, it is well known to pellet iron ore when processing iron ore. For example, in "'Pelletizing', Lurgi Metallurgie GmbH, Frankurt a.M., 1589e/6.97/20" or "'Innovation: SIMINE PELLET/Higher Productivity, Lower Costs an New Generation Pellet Plant', Andreas Lekscha, metals & minig, 2may2006, www. The so-called Lurgi-Davy-Travelling-Grate (Lurgi-Davy-Travelling-Grate) process known from siemens.com/minig" is the classic Wanderrostverfahren process: spherical raw Pellets are formed or rolled in drum pelletizers or pan pelletizers. The green pellets are dried in a reciprocating grate furnace or a sintering machine and finally fired or roasted at high temperature into finished pellets, ie fired pellets. the

FIG. 2 shows a known sintering machine 2 . In the known reciprocating grate process, green pellets GP—here iron ore pellets—are placed on a protective layer HL of already fired (iron ore) pellets FP. In this case, the suction zone AZ or the suction bellows AWk is located upstream of the pellet feed, at the machine end, ie at the machine head. In the direction of flow, the pellets are transported successively through the drying zone TRZ, heating zone WZ, combustion or sintering zone BRZ, waste heat utilization zone REZ and cooling zone KZ of the sintering machine. In the combustion zone BRZ the green pellets GP are converted into fired pellets FP. At the end of the machine, these pellets arrive on the output conveyor CO. the

The respective zones are separated from one another by fixed partition walls 4 . The cooling zone KZ has two subzones KZ1 and KZ2 which are equipped with a common wind box collector E. Fresh air 10 is supplied to the bellows collector via a blower F1 via a supply line 6 with an inlet 8 for fresh air 10 . Fresh air 10 is blown horizontally from bottom to top over the fired pellets FP located in the cooling zone KZ in the direction of the flow arrows shown in FIG. 2 (which also applies to the description below). During this process the fired pellets FP are cooled and the fresh air 10 is heated. The absorbed heat - using air as the heat carrier - is transported from the sub-zone KZ1 through the central main collector HK to the heating zone WZ and the combustion zone BRZ from above, and in order to assist the work of the burner BR in the combustion zone BRZ and the heating zone WZ to be used. This warm air supports the combustion process in which a fuel such as natural gas is burned in the burner BR. The warm air in the waste heat utilization zone REZ and the combusted gas in the combustion zone BRZ pass through the pellet bed and are then sucked out as hot air 18 through the collector C by the blower F3 through the second output duct 16 . The heat of this gas is used directly, that is to say without using additional blowers, to dry the green pellets GP in the subzone TRZ2 of the drying zone. In the subzone TRZ1 part of the gas is used for the same purpose by means of the blower F2. The gas, here the warm air 14 from the heating zone WZ and the sub-zone TRZ2, is sucked out and passed through the layer of green pellets GP by means of the first outlet duct 12 by means of the blower F5 through the collector B and the electrostatic filter ESP1 is sucked away and discharged into the atmosphere through the chimney K. the

The hot air 18 has a higher temperature than the warm air 14 and the warm air has a higher temperature than the fresh air 10 . the

The described sintering method or the sintering machine 2 according to the prior art only meets the technical, economical and ecological requirements of the time to a certain extent. The problem with this is that the partially fired pellets break down, or the pellets do not cool completely in the end, ie after passing through the sintering machine, and thus damage the subsequent discharge conveyor CO. the

For multiple technical purposes like cooling hot pellets in KZ1 and KZ2, regulating pressure in the upper part of the sintering machine, applying only one blower would lead to technical conflicts and make stable control of the technical process difficult. the

The known sintering machine 2 has other components which are not relevant to the invention and are therefore not explained in detail here. the

Utility model content

The purpose of the utility model is achieved by a sintering machine, which is characterized in that the sintering machine has a drying zone and is followed downstream by: a heating zone adjacent to the drying zone, adjacent to the heating zone The combustion zone adjacent to the combustion zone, the waste heat utilization zone and the cooling zone adjacent to the combustion zone, the sintering machine also has: a first output duct for discharging warm air from the drying zone and the heating zone; A second output duct for hot air exhausted from the combustion zone and the waste heat utilization zone; a pre-cooling zone arranged between the waste heat utilization zone and the cooling zone; an inlet for fresh air to the pre-cooling zone an input duct for inputting mixed air composed of fresh air, warm air and hot air into the cooling zone; and a connecting duct leading from the first output duct and the second output duct to the input duct. the

According to the invention, the sintering machine is a sintering machine for iron ore pellets, the sintering machine having a drying zone. Immediately downstream the drying zone has an adjacent heating zone. Downstream of the heating zone is a combustion zone; further downstream is a waste heat utilization zone adjacent to the combustion zone. The cooling zone is immediately downstream of the waste heat utilization zone. The first output pipe discharges warm air from the drying area and the heating area, and the second output pipe discharges hot air from the combustion area and the waste heat utilization area. A pre-cooling zone is provided between the waste heat utilization zone and the cooling zone known to date, which is composed of the subzones KZ1 and KZ2. The sintering machine additionally has an inlet line which in turn has an inlet for fresh air. This inlet pipe delivers a mixture of fresh air, warm air and hot air to the precooling zone. In addition, the sintering machine comprises connecting ducts leading from the first and second output ducts to the input ducts. The connecting duct thus conveys warm air from the first outlet duct to the inlet duct and hot air from the second outlet duct to the inlet duct, so that the corresponding warm and warm air is mixed with fresh air there. the

The position of the pre-cooling zone "between" the waste heat utilization zone and the cooling zone "actually formed by the sub-zones KZ1 and KZ2" can be realized in two alternative ways, according to the definition of the cooling zone according to the utility model: known The cooling zone is actually shortened and its sub-zones KZ1 and KZ2 follow the pre-cooling zone. the

Strictly speaking, the connecting duct can also include an inlet for fresh air. The input pipe thus degenerates into a part of the connection pipe. It is important that only fresh air, warm air and hot air are mixed and this mixed air is conveyed to the pre-cooling zone via a suitable duct system. the

The utility model relates to the recognition that, on the one hand, there is a significant temperature drop between the combustion zone with the waste heat utilization zone and on the other hand the cooling zone, and that, in the corresponding process, the fired pellets due to this The temperature drop is subject to sudden temperature changes, which often lead to the breakdown of the pellets. The utility model relates to the basic knowledge that a large amount of heat in the form of warm air is generally unused from the second section TRZ2 of the drying zone and the heating zone WZ into the atmosphere through the blower F5 and the chimney K, wherein The temperature of the heat carrier here is approximately 160°C. the

Thus, according to the present invention, a pre-cooling zone is realized between the waste heat utilization zone and the cooling zone. This can be achieved, for example, by splitting the known bellows collector E (section E, section D), wherein the feed line opens into section D. The precooling zone is thus adjustable independently of the cooling zone with regard to the mixing temperature of the mixed air and the amount of air flowing through it. This ensures better selectivity of the entire cooling process. The sudden change in temperature of the pellets is reduced by, that is, when the temperature of the cooling gas in the pre-cooling zone is between the relative degrees of the combustion zone, the waste heat utilization zone and the cooling zone, the elapsed time variation process, that is , a uniform or graded cooling of the pellets is achieved by the sintering machine during the passage. At the same time the drying heat and part of the heat from the combustion zone are productively used by connecting pipes from the two output pipes to the inlet pipes. the

The result will be fewer popped or broken pellets and thereby improve the quality of the finished pellets and the specific efficiency of the manufacturing process. This allows greater technical flexibility for the cooling process in the sintering machine, as well as better use of the waste heat already present in the process, and thus reduces fuel consumption through a more rational use of this heat. Therefore, productivity is improved, running costs are reduced, and environmental burdens are reduced. the

In a preferred embodiment of the present invention, the input pipe includes a blower. By controlling the blower, it is also possible to influence the quantity of mixed air actually conveyed in the precooling zone. The degree of freedom in the operation of the sintering machine is improved. In the sintering machine, a new blast circulation is thus achieved in the precooling zone. the

By incorporating a further blower in the cooling zone of the machine, the cooling zone and the precooling zone can be independently controlled on the one hand separately with respect to the air throughput in the cooling zone and the precooling zone. Since not only the blower in the precooling zone but also the blower in the cooling zone feeds air into the main collecting device and thus influences the pressure above the burner, it is now also possible here with two blowers in the heating zone WZ, the combustion zone BRZ and pressure regulation above the burners in the cooling zone KZ1. the

In an advantageous variant of the embodiment of the invention, the connecting line is connected to a suction-side section of the supply line. the

In an advantageous variant of this embodiment, the connecting line is then connected—with reference to the position of the blower in the outlet line—to the suction-side section of the inlet line. The suction power of the blower fed into the duct is thus used to draw warm and hot air through the connecting duct. the

In an advantageous variant of the embodiment of the present utility model, the first output duct and the second output duct comprise blowers, and the connecting duct is connected to the first output duct and/or the second output duct. On the section of the pressure side of the second output pipe. the

Typically, the first and/or second output duct also includes a blower. In a preferred embodiment, the connecting line is then connected in each case to a pressure-side section of the first and/or second outlet line, that is to say to the blower side of the blower. the

In an advantageous variant of the embodiment of the invention, the sintering machine has a control device for controlling the proportions of the warm air, the hot air and the fresh air in the mixed air. the

In another preferred embodiment, the sintering machine comprises a control device for controlling the proportions of warm air, hot air and fresh air in the mixed air. This control device is most often a valve, which can be arranged in the connecting line or in the supply line. A desired mixing temperature of the mixed air can thus be set between the temperature of the fresh air and the temperature of the hot air. the

In an advantageous variant of the embodiment of the invention, the sintering machine has regulating means for regulating the mixing temperature of the mixed air by acting on the control means. the

In a variant of this embodiment, the sintering machine also includes a regulating device, which acts on the control device in such a way that the mixing temperature of the mixed air is regulated - usually kept almost constant at a presettable target value . This enables uniform mixing temperatures and thus constant production quality or production conditions. A suitable mixing temperature is possibly eg about 100°C. the

In an advantageous variant of embodiment of the invention, the sintering machine has a suction cooling zone arranged downstream of the cooling zone, and a third output for discharging dust-laden air from the suction cooling zone pipeline. the

In a preferred embodiment of the invention, in the sintering machine, downstream of the cooling zone, a suction air cooling zone AC is additionally provided, which has associated wind boxes. The intake air cooling zone is associated with a third discharge line which discharges the dust-laden gas from the intake air cooling zone. the

In the cooling zone, the pellets below are usually sufficiently cooled since the cooling air flows from below towards the pellets. At this point, the upper pellets are less cooled. The creation of the additional air suction cooling zone AC provides the possibility to use the air to flow through the pellets from above and simultaneously suck out the accumulated dust there. This results in better cooling of the hitherto hotter upper pellet layer. The temperature difference in the pellet layer in the vertical direction is reduced so that temperature compensation takes place especially between the upper and lower pellets. In conclusion, the pellets leaving the machine thus all have almost the same temperature. Damage to the output conveyor belt due to individual overheated pellets is avoided. the

In an advantageous variant of the embodiment of the invention, the third discharge line is connected to a suction blower of the sintering machine which is additionally assigned to a different zone than the suction cooling zone. the

In a preferred variant of this embodiment, the third outlet line is connected to a suction blower, wherein the suction blower next to the suction cooling zone is additionally also assigned to a different suction blower of the sintering machine. Zone of cooling zone. Such a suction blower is also assigned to the suction area in the cooling chamber, for example at the end of the conveyor belt. In other words, this existing blower is therefore shared for the suction air cooling zone. the

In an advantageous variant of embodiment of the invention, said sintering machine is a sintering machine for iron ore pellets. the

In a preferred embodiment, the area ratio between the suction zone AZ at the upstream end of the sintering machine and its downstream adjacent drying zone (TRZ) has a defined value. In other words, the drying zone at the upstream end of the machine is extended due to the cost of the suction zone present there. This increases the drying area in the drying zone. This variant involves the recognition that in known machines there is a hitherto underused reserve area for transporting away dust and for providing a suction area there. The discharge unit (suction bellows AWk) used for this purpose can be connected to a suitable blower. By reducing and/or shifting the suction surface, the newly obtained area is then connected upstream to the existing drying surface, and the latter is thus larger according to the invention compared to known machines. The two subzones TRZ1 and TRZ2 of the drying zone are varied here by another suitable proportion, in particular both are enlarged. The pellets are dried more evenly and better and are thus better suited for other processing flows. the

Description of drawings

The characteristics, features and advantages of the present invention described above, as well as the manner and method for achieving these features and advantages, will become clearer and more comprehensible through the following description of the embodiments illustrated in more detail by the accompanying drawings. It is shown in the schematic schematic diagram:

Fig. 1 is the sintering machine obtained according to the expansion of the utility model from Fig. 2,

Figure 2 shows a sintering machine according to the prior art. the

Detailed ways

FIG. 1 shows an expansion 20 according to the invention of the known sintering machine 2 from FIG. 2 . For this purpose, the known bellows collector E at its upstream end is shortened. Here, an additional wind box collector D is installed, whereby the first subzone KZ1 of the cooling zone KZ is also shortened. This creates a precooling zone VKZ in its place. According to the considerations, the cooling zone KZ, which is otherwise formed by the subzones KZ1 and KZ2, is thereby shortened and a precooling zone VKZ is added between this cooling zone and the waste heat utilization zone REZ. In another equivalent consideration, the cooling zone KZ is connected unchanged to the waste heat recovery zone REZ. The subzone KZ1 is then shortened and a precooling zone VKZ is added as a subzone of the cooling zone KZ. In FIG. 1 , this is indicated between the waste heat utilization zone REZ and the cooling zone KZ by a dividing line in parentheses. the

The precooling zone is supplied with mixed air 26 in the direction of arrow 24 via the wind box collector D and the supply duct 22 . The feed line 22 has an inlet 8 for the fresh air 10 . The input line 22 is additionally connected to the first output line 12 and the second output line 16 via a connecting line 28 . The connecting line 28 is designed in two parts and thus opens into two different points of the supply line 22 . the

Warm air 14 and hot air 18 are fed from first outlet line 12 and second outlet line 16 via connecting line 28 into input line 22 in the direction of arrow 24 and are mixed there with fresh air 10 to form mixed air 26. the

With respect to the first outlet line 12 and the second outlet line 16 , the connection line 28 or its corresponding sub-branch is connected to its pressure-side section 30 b , ie on the pressure side of the blower F3 , F4 in each case. The warm air 14 and the hot air 18 are thus conveyed via the connecting line 28 using their pressure effect. the

In a preferred embodiment, the feed line 22 includes a blower F6 and thus a suction-side section 30 a and a pressure-side section 30 b associated with this blower. The connecting line 28 then opens into the first suction-side section 30a of the inlet line 22 . The suction effect of the blower F6 is thus not only used to draw in fresh air 10 through the supply line 22 , but also to draw in warm air 14 and hot air 18 through the connection line 28 . the

In a preferred embodiment, the connecting line 28 and/or the inlet line 22 comprise a corresponding control device 32 - here a valve - which controls, on the one hand, the The corresponding quantities of fresh air 10 , warm air 14 and hot air 18 are delivered. The corresponding proportion of these airs in the mixed air 26 is thus controlled. the

In a preferred embodiment, the regulating device 34 is assigned to one or more of the control devices 32 . This regulating device controls the associated control device 32 in such a way that the mixing temperature TM of the mixed air 26 is set to the desired value S. FIG. The mixing temperature TM is here in the range of the temperature TF of the fresh air 10 , the temperature TW of the warm air 14 and the temperature TH of the warm air 18 . Because the following conditions are met during the operation of the sintering machine: TF<TW<TH, so TF≤TM≤TH. the

In a preferred embodiment, an extension 20 of the known sintering machine 2 from FIG. 2 also results in the introduction of the suction air cooling zone AC according to FIG. 1 . This suction air cooling zone follows the known cooling zone KZ. This is achieved by implementing a third outlet duct 36 which discharges dust-laden air 38 from the intake air cooling area AC in the direction of the arrow 24 . The flow of the fired pellets FP through the suction cooling zone AC takes place vertically from top to bottom (see flow arrows in FIG. 1 ), ie counter to the flow direction in the cooling zone KZ. This compensates for the temperature profile of the fired pellets FP layered above and below during the cooling process in the vertical direction. the

In a preferred embodiment, the third outlet line 36 is connected to a suction blower FA which, in known machines, is assigned to the rear suction bellows AWh. Initially, this blower was assigned to a zone of the sintering machine 2 that differs from the suction air cooling zone AC, whereas now the suction air cooling zone AC is simply made to share this blower. the

In a preferred embodiment, the suction bellows AWk at the upstream machine end and thus the suction zone AZ are reduced compared to known machines, whereas the drying zone TRZ is enlarged instead. In an embodiment not shown, the suction zone AZ is also moved only upstream in the hitherto unused machine area. The drying zone TRZ is extended in the machine longitudinal direction and thus its area FT is enlarged. The area ratio specified here between the area of the air intake area FA and the area FT of the drying zone TRZ is the area ratio F, which here represents a defined value. In this case, the subzones TRZ1 and TRZ2 are each generally enlarged to themselves. This provides a larger area for drying of the green pellets GP in the drying zone TRZ, resulting in better and more uniform drying of the green pellets. the

Although the details of the present invention have been illustrated and described in detail by preferred embodiments, the present invention is not limited to the disclosed examples, and those skilled in the art can deduce therefrom without departing from the protection scope of the present invention. other variants. the

Claims (15)

1. A sintering machine (2), characterized in that the sintering machine has a drying zone (TRZ) and immediately downstream a heating zone (WZ) adjacent to the drying zone, connected to the heating zone Adjacent to the combustion zone (BRZ), a waste heat utilization zone (REZ) and a cooling zone (KZ) adjacent to the combustion zone, the sintering machine also has: from the drying zone (TRZ) and the heating zone (WZ) to discharge warm air (14) from a first output duct (12); and a second output duct to discharge hot air (18) from said combustion zone (BRZ) and said waste heat utilization zone (REZ) ( 16); a pre-cooling zone (VKZ) arranged between said waste heat utilization zone (REZ) and said cooling zone (WZ); with an inlet (8) for fresh air (10) to said pre-cooling zone (VKZ) into the input duct (22) of mixed air (26) consisting of fresh air (10), warm air (14) and hot air (18); and from said first output duct (12) and said Said second output conduit (16) leads to a connecting conduit (28) of said input conduit (22). the 2. The sintering machine (2) according to claim 1, characterized in that the input pipe (22) comprises a blower (F6). the 3 . The sintering machine ( 2 ) according to claim 2 , characterized in that the connecting line ( 28 ) is connected to a suction-side section ( 30 a ) of the inlet line ( 22 ). 4 . the 4. The sintering machine (2) according to any one of claims 1 to 3, characterized in that, the first output pipe (12) and/or the second output pipe (16) comprises a blower (F5 , F3), and the connecting line (28) is connected to the pressure-side section (30b) of the first output line (12) and the second output line (16). the 5. The sintering machine (2) according to any one of claims 1 to 3, characterized in that the sintering machine has the function of controlling the warm air (14), the heat A control device (32) for the share of air (18) and the fresh air (10). the 6. The sintering machine (2) according to claim 4, characterized in that the sintering machine has the function of controlling the warm air (14), the hot air (18) and the Control device (32) for the share of fresh air (10). the 7. The sintering machine (2) according to claim 5, characterized in that the sintering machine has a mixing temperature (TM) for adjusting the mixing temperature (TM) of the mixing air (26) by acting on the control device (32) The adjustment device (34). the 8. The sintering machine (2) according to claim 6, characterized in that the sintering machine has a mixing temperature (TM) for adjusting the mixing temperature (TM) of the mixing air (26) by acting on the control device (32) The adjustment device (34). the 9. The sintering machine (2) according to any one of claims 1 to 3, characterized in that the sintering machine has a suction cooling zone (AC) arranged downstream of the cooling zone (KZ), and A third output duct (36) for discharging dust laden air (38) from the suction cooling zone. the 10. The sintering machine (2) according to claim 8, characterized in that the sintering machine has a suction cooling zone (AC) arranged downstream of the cooling zone (KZ), and from the suction cooling A third output duct (36) for discharging dust-laden air (38) from the zone. the 11. The sintering machine (2) according to claim 9, characterized in that the third output pipe (36) is connected to the sintering machine (2) and is additionally assigned to the suction cooling zone ( AC) on different zones of the suction blower (FA). the 12. The sintering machine (2) according to claim 10, characterized in that, the third output pipe (36) is connected to the sintering machine (2) which is additionally assigned to the suction cooling zone ( AC) on different zones of the suction blower (FA). the 13. The sintering machine (2) according to any one of claims 1 to 3, characterized in that the suction zone (AZ) on the upstream end of the sintering machine (2) is connected to the suction zone The area ratio (F) between downstream adjacent drying zones (TRZ) has a defined value. the 14. The sintering machine (2) according to claim 12, characterized in that the suction zone (AZ) on the upstream end of the sintering machine (2) is drier adjacent to the suction zone downstream. The area ratio (F) between the zones (TRZ) has a certain value. the 15. The sintering machine (2) according to any one of claims 1 to 3, characterized in that the sintering machine (2) is a sintering machine for iron ore pellets (GP, FP). the

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